Hair-spring collet for watches



J (No Model.)

W. B. BANTA. HAIR SPRING'OOLLET FOR WATCHES.

No. 438,672. Patented Oct. 21, 1890.

UNITED STATES PATENT OFFICE.

IVILLIAM E. BANTA, OF SPRINGFIELD, OHIO.

HAIR-SPRING COLLET FOR WATCHES.

SPECIFICATIONforming part of Letters Patent No. 438,672, dated October21, 1890.

Application filed June 23, 1887- Serial No. 242,226. (No model.)

To all whom, it may concern.-

Be it known that 1, WILLIAM E. BANTA, a citizen of the UnitedStates,residin g at Springfield, in the county of Clark and State ofOhio, have invented certain new and useful Improvements in Hair-Springsfor \Vatches, of which the following is a specification, reference beinghad therein to the accompanying drawings.

This invention relates to improvements in watch hair-springs; and theobject I have in viewis to so construct the collet that the spring maybe quickly, cheaply, and strongly secured thereto without bending thespring at sharp angles or forming holes therein.

Vith this end in view my invention consists, essentially, of an annulusforming the collet and having an incision therein into which the springis fitted, and so fashioned that the spring passes from within itconveniently round the periphery of the collet.

The invention further consists of the collet having an incision therein,and the spring in the incision, and held by a part of the collet beingcompressed against it.

In the accompanying drawings, forming a part of this specification, andon which like reference-letters indicate corresponding features, Figure1 represents an enlarged plan view of my improved collet with a springsecured therein; Fig. 2, a perspective view of the collet alone; Fig. 3,a vertical sectional view of the collet; Fig. 4, a plan view of acollet, showing a modified form of incision; and Fig. 5, a sectionalview of the collet and spring, showing the former clinched over thelatter.

The letter A refers to a metallic annulus, either divided, as seen at B,or contiguous throughout, and which forms the hair-spring collet of awatch, the central hole in it servin g to receive the shaft that carriesthe spring. The slot at B enables the collet to be compressed tightlyround its shaft, though of course it may be otherwise secured in theabsence of the slot. In one end of the collet, preferably the upper, Iform in any convenient manner an incision O of sufficient depth toreceive the width of one end of the hairspring D. The direction of thisincision is preferably eccentric to the periphery of the collet, wherebyit terminates at one or both ends at the periphery to allow of thespring extending conveniently and withoutinterruption from the incisionto and against and round the periphery, substantially in the m annershown in Fig. 1. This is the preferred form; but my invention does notstop with the particulardirection of the incision. Therefore I haveshown in Fig. at the incision concentric to the periphery of the collet,and, have made a depression E therein to allow the spring to readilyreach the periphery. The spring may maintain itself in position by thefit between it and the incision; but I prefer to compress the thin walloutside of the incision firmly against the spring, and, more than this,that wall may be somewhat clinched over the edge of the spring, as seenin Fig. 5.

It will be seen from Fig. 2 that the incision in entering upon theperiphery leaves two tapering shoulders F. The one of these from whichthe spring projects serves to support still farther round the collet.

Among the practical advantages of my collet may be noted its extremeeheapness and conspicuous simplicity of construction, its adaptation notonly to firmly hold the hairspring without in anywise boring, rebending,and changing it, but also the ease and quickness with which the springcan be inserted, and the fact that it can also be removed shouldoccasion require.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. A watch hair-spring collet constructed with an incision in one facethereof which runs eccentric to the periphery and into it and is adaptedto receive and hold a hairspring.

2. An annulus which forms a hairspring collet for a watch, constructedwith an incision in one face thereof which runs eccentric to theperiphery and into it and leaves a tapering shoulder for the spring.

3. A watch hair-spring 'coilet constructed fitted into'said incision andheld therein by with an incision in one face thereof and near thecompressible part of the collet. :0 the periphery, so as to leave a walladapted In testimony whereof I affix my signature to be compressedinward to clamp the spring. in presence of two witnesses.

5 4. A hair-spring coilet having an incision WILLIAM E. BANTA.

in the face thereof, leaving a partbetween Witnesses: the incision andthe periphery which is coni- WILBER COLVIN,

pressible toward the center, and a hair-spring C. M. KIssELL.

